Hot Start Issue / Flooding

FRED · 07-20-2011, 05:18 PM

Why would one change the water thermo sensor????????? IF a water thermosensor fails the ECU defaults to a hot temperature which is 178* if memory serves. Makes no sense to change it.

ECU codes cannot detect a low compression engine. Theres no reason to suggest the water thermo sensor is bad code or no code. Easy to check out though. On a normal car the sensor outputs approx .5 or a half volt at the ECU with a hot engine. No reason to think it's bad though.

Reread what RETED wrote about RX and flooding.

There's no solenoid resistor on series five car or series four built after the middle of 1987. NOT a player anyway.

I've been thru this in the past and viewed it with a meter. I got a engine up to full temp and turned it off. Then disconnected the START signal to the ECU. Then started the car and viewed the pulse width of the primary injectors on a meter while cranking the engine over (ignition disabled so it would not start up). The pulse width was 5.96 ms.

Then put the wire back on the ECU and cranked the engine over. The pulse width of the injectors was 17.62 ms.

Now which case above would be the least likely to flood an engine? The 5.96 ms of course. The AFM is being used for fuel in this case and the internal fuel map is being used when the wire was back on the ECU and the pulse width was 17.62 ms.

Just my way of showing what happens if the ECU never sees the Start signal. Virtually no chance of the engine flooding when hot. None imho.

I can see you want to just change parts to fix this problem. Ain't a gonna happen but have at it. I through here. Done my part. Gone. Last suggestion is to build a fuel cut switch to make a temp fix. Usually works every time once you get the hang of it.

07-20-2011, 05:18 PM	#9
FRED Rotary Fan in Training Join Date: Mar 2011 Posts: 73 Rep Power: 15	Why would one change the water thermo sensor????????? IF a water thermosensor fails the ECU defaults to a hot temperature which is 178* if memory serves. Makes no sense to change it. ECU codes cannot detect a low compression engine. Theres no reason to suggest the water thermo sensor is bad code or no code. Easy to check out though. On a normal car the sensor outputs approx .5 or a half volt at the ECU with a hot engine. No reason to think it's bad though. Reread what RETED wrote about RX and flooding. There's no solenoid resistor on series five car or series four built after the middle of 1987. NOT a player anyway. I've been thru this in the past and viewed it with a meter. I got a engine up to full temp and turned it off. Then disconnected the START signal to the ECU. Then started the car and viewed the pulse width of the primary injectors on a meter while cranking the engine over (ignition disabled so it would not start up). The pulse width was 5.96 ms. Then put the wire back on the ECU and cranked the engine over. The pulse width of the injectors was 17.62 ms. Now which case above would be the least likely to flood an engine? The 5.96 ms of course. The AFM is being used for fuel in this case and the internal fuel map is being used when the wire was back on the ECU and the pulse width was 17.62 ms. Just my way of showing what happens if the ECU never sees the Start signal. Virtually no chance of the engine flooding when hot. None imho. I can see you want to just change parts to fix this problem. Ain't a gonna happen but have at it. I through here. Done my part. Gone. Last suggestion is to build a fuel cut switch to make a temp fix. Usually works every time once you get the hang of it.